The present invention relates to processes for creating photomasks which are used in integrated circuit manufacture. Specifically, a process is described for creating a photomask exposure data file for defining objects on a photomask.
The process of manufacturing integrated circuit masks which are used in photolithographic techniques to define semiconductor structures on a substrate relies upon the generation of one or more pattern files that define the exposure areas of the photomask as well as a Job Deck or similar file, depending on the specific exposure tool that is used. The layout for the photomask is created from the pattern files, such as a Moving Electron Beam Exposure (MEBES) data file. The data is based on specific designer inputs which define functional logic and which are subsequently modified for particular semiconductor processes and vendor equipment. The design specification created by the circuit designer is used as an input for algorithms which define photomask structural details.
Using a conventional data conversion and manipulation (fracturing) software, such the Computer Aided Transcription System (CATS) from Transcription Enterprises, Ltd., the designer's input in the form of levels is subjected to an algorithm which defines the photomask structures. A series of CATS Include Files are created from the results of combining the algorithm with information about the input data, and these Include files are then passed to the CATS execution software which performs the operations and produces the pattern data. Various mask creating tools use this pattern data (which can vary based on the specific tool used) to create masks defining the particular regions to be created on a semiconductor substrate to obtain the designer's specified circuit functionality.
As the volume of data which is necessarily entered to create these Include files involves several people using several processes, errors are likely. Automating the process of creating the CATS Include Files reduces mask errors, correspondingly increasing yields and reducing processing time.
The present invention further automates the process of creating the CATS Include Files so that user inputs are held to a minimum, reducing the errors and subsequent inefficiency of mask production.
The algorithms which define the photomask structures can be more efficiently processed if the Include files are created (and controlled) to enhance parallel processing. The process of creating the Include Files is therefore advantageously structured to create numerous include files that can be executed in parallel, thus further improving the efficiency of mask production.